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Online Timer: Countdown with Alarm Sound

Set a countdown in hours, minutes and seconds, with an alarm sound, full screen and presets from 1 to 60 minutes. It keeps exact time even in a background tab.

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Pasta, oven, speech or plank: give the timer a name and the browser tab shows it next to the time left, so you can check on it from any other tab. When time is up, the progress ring turns red, the sound you picked plays for up to a minute and a counter shows how far past zero you are. “+1 min” extends the countdown without restarting it, the space bar pauses it, and a link passes the duration and the name on to someone else. This page can't ring from a closed tab, a sleeping device or a locked iPhone: the limits section below says exactly what will sound and what won't.

How to use it

  1. Set the duration in the “Hours”, “Minutes” and “Seconds” boxes, or click one of the nine quick durations (1, 2, 5, 10, 15, 20, 30, 45 or 60 min): that chip starts the countdown straight away.
  2. Type a name in “Timer name”, for example Pasta: it appears above the ring, in the tab title and, if you turned it on, in the end notification.
  3. Under “End sound”, pick one of the five sounds, set the volume, then press “Test sound”: that click also gives the browser permission to play audio.
  4. Launch the countdown with “Start”. Along the way, “Pause” freezes the time left and “Resume” carries on from there; “+1 min” adds a minute, and “Reset” (R key) returns to the duration you set.
  5. When it rings, silence it with “Stop the alarm” or the Esc key; “Start again” then reruns the duration you set. For a bigger display, “Full screen” (F key) blows the ring up to fill the screen.

What happens between “Start” and the alarm

Pressing “Start” doesn't set off a counter that takes one second away on every beat: the page fixes an end time, now plus the duration. Four times a second it subtracts the current time from that deadline and rounds up to the whole second, so 10:00 stays on screen for the entire first second and 00:00 only appears at the very end. If the browser spaces those refreshes out, the next one is still right. The end is dated at the planned deadline, not at the moment the page notices it, so the overtime counts from the real end. “Pause” stores the time left; “Resume” works out a new deadline.

The alarm is synthesized by the browser's audio engine; no sound file is involved. Once the deadline is two minutes away or less, the alarm is scheduled in that engine for the exact end time, for one minute: the engine isn't held back the way a page's timers are, whereas Chrome may wake a hidden tab only once a minute. On every refresh the page checks that schedule and sets it again if it has drifted more than a quarter of a second from the deadline, if you changed the sound, if the tab becomes visible again or if the computer slept, which it spots from a gap between the system time and the browser's internal clock.

The rest helps you follow the time without staying in front of it: the tab title shows ▶ with the time left and the name, if any, ⏸ while paused and ⏰ at the end; during the countdown the page asks the browser to keep the screen on, where supported; and if you turned notifications on, one can appear when the tab is hidden at the deadline. On iPhone, where Safari keeps true full screen for videos, “Full screen” stretches the ring across the whole window.

Where a countdown comes in handy

  • Two dishes at once: open the tool in two tabs, name one Pasta (10 min) and the other Oven (45 min). Each tab title shows its own time left and each page schedules its own alarm, on a computer at least, since Safari on iPhone mutes a page that isn't on screen.
  • Plank sets or skipping rounds: click 1 min, and each time the alarm goes off the big button reads “Stop the alarm”, then “Start again”: two presses and the next set runs for the same length.
  • Fixed speaking time, for a thesis defense, a three-minute pitch or a round of introductions: put the timer in full screen facing the speaker. Once time is up, “Over by” counts the extra seconds, so you know exactly how far each person ran over.
  • A class test or mock exam: type 90 in “Minutes” and project the ring in full screen; at a glance, everyone sees how much of the time has gone, and the alarm tells them when to put their pens down.
  • Board games, drawing-and-guessing games or quizzes: one click on the 1 min or 2 min quick duration starts the turn, and clicking the same chip again restarts the countdown at once, even if it hadn't finished.
  • A coffee break in a video call: set 10 minutes, name the timer Coffee, press “Copy” under “Share this timer” and paste the link into the chat. Everyone opens the same duration with the same name but starts their own countdown: nothing is synchronized.

What the screen shows, case by case

  • A named timer: set the boxes to 00, 05 and 00, enter Pasta as the name and press “Start”. One second later, the tab reads ▶ 04:59 · Pasta. Thirty seconds after the deadline, the ring shows 00:00, “Time's up” and “Over by +00:30”, and the tab reads ⏰ Time's up · Pasta.
  • Pausing: a 10-minute timer, “Pause” after 3 minutes. The ring shows 07:00 and “Paused”, the tab ⏸ 07:00, and they still do 50 minutes later. Clicking “Resume” sets the new end 7 minutes after that click; a minute on, 06:00 remains.
  • “+1 min” near the end: a 2-minute timer shows 00:20; one click on “+1 min” takes it to 01:20 and pushes the end back a minute. During the alarm, the same button silences it and starts a fresh 01:00 countdown.
  • More than an hour: 90 in “Minutes”, with 00 in the other two boxes, gives 1:30:00 on the ring. 99 in “Hours” plus 60 in “Minutes” makes 100 hours, so the message “The duration can't exceed 99:59:59” appears and “Start” does nothing.

What a browser can't guarantee

  • The page has to stay open: closing the tab or reloading the page ends the countdown, and no alarm will come. When you return, only the sound, the volume, the notification setting and the last duration you started are remembered, if the browser agrees to save them; you have to start again.
  • A sleeping device doesn't ring: the audio engine stops along with it. On waking, an end that passed a minute or more ago stays silent; sooner than that, the page tries to play what's left of the alarm, with no guarantee. If nothing had been scheduled yet, the arithmetic is simple: 15 seconds late leaves 45 seconds of alarm.
  • On iPhone and iPad, sound cuts out once Safari is sent to the background or the device locks. Depending on the phone, silent mode, media volume turned all the way down or a battery saver can also make the alarm inaudible or put the page to sleep.
  • Sound is only allowed after you do something: a search or a link sets the duration without starting anything, and if the browser still blocks audio, a red message asks you to press “Test sound”.
  • Notifications are optional: you have to allow them, they only fire if the tab is hidden at the end, and Chrome on Android may not show them from a web page at all. They appear when the page notices the end, which can lag in a tab that has been hidden for a while.
  • One timer per page, up to 99:59:59, shown to the second. While it runs or is paused, the duration boxes are locked, but clicking a quick duration replaces the current timer without asking.

Privacy

Processed in your browser

The countdown, the name and the alarm all run in your browser: nothing you type is sent. Under the allin_tools key, your browser keeps the sound, the volume, the last duration you started and your notification setting, but not the name. The site records anonymous usage events (page viewed, timer started, timer finished, sound blocked, link copied) with the device type, the country worked out without storing your IP address and a random identifier erased when the tab closes; never the duration or the name. The share link contains the duration and the name, which anyone who receives it will see; the name sits in a part of the address that the browser doesn't send to the server when the link is opened.

Frequently asked questions

If I switch to another tab, will the timer still ring?

Yes, as long as the page stays open and the device doesn't sleep. The time left is worked out from the end time, so a tab the browser slows down gets the right value back on every refresh. And once two minutes remain, the alarm is handed to the audio engine, which plays it on time without waiting for the page to wake up. The exception is iPhone and iPad, where Safari mutes a page that's no longer on screen.

Does the countdown keep going if I reload or close the page?

No: nothing runs outside the page, so the countdown stops and no alarm will come. When you return, the boxes offer the last duration you started, along with the sound, volume and notification setting you chose; the name isn't kept. You have to press “Start” again, and the count begins from the full duration, not from the time that was left.

Why didn't the timer make any sound?

Check in this order: the “Volume” slider or the device volume at zero; audio blocked by the browser, flagged by a red message under the buttons and cleared with “Test sound”; a closed tab or a sleeping device at the deadline; Safari sent to the background on iPhone. Finally, if the page only noticed the end a minute or more after the planned time, it doesn't ring at all.

How long does the alarm ring, and how do I stop it?

It rings for a minute at most from the planned time, then stops on its own. To cut it short, press the big red “Stop the alarm” button or Esc. “+1 min” silences it too and immediately starts one more minute, handy when the dish isn't quite done. Once it's quiet, the button reads “Start again” to rerun the duration you set.

How do I set more than an hour, say an hour and a half?

The quick durations stop at 60 min, but the boxes go up to 99:59:59. Type 1 in “Hours” and 30 in “Minutes”, or simply 90 in “Minutes”: both show 1:30:00. The minutes box takes up to four digits and the hours box two. Before you start, “+1 min” adds a minute to what you've entered without launching anything.

Can I open a timer that's already set, for example to 10 minutes?

Yes. The site's search understands “10 minute timer” and offers the tool with 00, 10 and 00 in the boxes; a link copied from “Share this timer” reopens the duration and the name. Either way, nothing starts by itself: browsers only play sound after you've interacted with the page, so it's your click on “Start” that sets the countdown going.

Can I run several timers at the same time?

Not on the same page, which handles a single countdown. Open the tool in a second tab and give each timer a name: the tab titles show the time left followed by the name, which is enough to tell them apart, and each page schedules its own alarm. On iPhone and iPad, though, only the tab on screen can ring, because Safari mutes the others.

Will my screen go to sleep during the countdown?

While the timer runs, the page asks the browser to keep the screen on, wherever that feature exists. The browser drops the request as soon as you switch away from the tab, and the page renews it when you come back; while paused or once time is up, it no longer asks. Without that feature, set your device's sleep delay longer than the timer: on a phone, a locked screen can stop the alarm from sounding.

Further reading

All guides →
ExplainerDate Arithmetic Is Harder Than It Looks"One month later" has no single correct answer, and every date library has had to pick one. Month addition is neither associative nor invertible, a day is not always 24 hours, and age is not days divided by 365.25.ExplainerLeap Years: The Rule, the Exception, and the Exception to the ExceptionDivisible by four, except centuries, except centuries divisible by four hundred. The three-line rule exists because the tropical year is not 365.25 days, and the arithmetic behind it explains ten deleted days in 1582 and a calendar that repeats exactly every 400 years.ExplainerWorking Out an AnniversaryCounting back and counting forward are two different sums, and they disagree by a year on the day itself. What this calculator does with 29 February, what other date libraries do, and where the traditional and modern gift lists actually come from.GuideThe Pomodoro Method: How Long to Work and How Long to RestTwenty-five and five come from Francesco Cirillo's method, not from a trial. What the research actually measured is task switching and the cost of getting back in — and the reason a fixed interval helps is not that 25 minutes is optimal. Plus what the planner really returns, including the long break it quietly leaves out.GuideWhat a Meeting Costs the Company, and What the Number Is ForSalary is not the cost. The ticker applies no loaded-cost multiplier of its own, so the rate box is where you have to put it. And the number is for one comparison: a recurring meeting against the written update that would replace it.GuideSchool Holiday Zones: Which One Applies to YouIn France only two of the six holiday periods differ between zones — and those two are two weeks apart from end to end. In Germany the summer break start spans thirty-five days between Länder. Neither can be computed: they are decreed, and a stale copy is the real hazard.